Safety inner tube for pneumatic tires



April 20, 1948. MADDQX SAFETY INNER TUBE FOR PNEUMATIC TIRES 2Sheets-Sheet 1 Filed July 6, 1945 April 20, 1948. N. R. MADDOX SAFETYINNER TUBE FOR PNEUMATIC TIRES Filed July 6, 1945 2 Sheets-Sheet 2Patented Apr. 20, 1948 UNITED SAFETY INNER TUBE FOR PNEUMATIC TIRESNorval Robert Maddox, Owingsville, Ky. Application July 6,1945, SerialNo. 603,430

2 Claims., ((1152-33) The present invention relates to new and usefulimprovements in pneumatic tires, and more particularly to a safety innertube of a, type which is constructed of a plurality of flexiblepartitions defining annular compartments, each of which is independentand separately inflated so that in 'the event one compartment should bepunctured,

the rest will be unaffected and the form or riding qualities of the tirewill be undisturbed.

An important object of the present invention is to provide an air valvefor an inner tube of this character whereby the several compartments maybe uniformly inflated.

Another object of the invention is to provide a device of this characterof simple and practical construction, which is eflicient and reliable inuse, relatively inexpensive to manufacture, and otherwise well adaptedfor the purposes for which the same is intended.

Other objects and advantages reside in the details. of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming part hereof. wherein likereference numerals refer to like parts throughout, and in which:

Figure 1 is a transverse sectional view of an inner tube showing theinflating valve for the several compartments,

Figure 2 is a similar view showing the position of the partitions whenone of the compartments is deflated.

Figure 3 is an enlarged vertical sectional view of the inflating valvefor the several compartments,

Figure 4 is a sectional view taken substantially on a hne 4-4 of Figure3, and

Figure 5 is a sectional view of a modified valve construction for useupon drop-center wheels.

Referring now to the drawings in detail, and first with respect to theform of invention illustrated in Figures '1 to 4, inclusive, the numeralI designates an inner tube for mounting in a tire casing 6, the innertube being provided with a plurality of circumferentially extending,flexible rubber partitions l separating the inner tube into a pluralityof circumferentially extending air chambers 8.

In order that the several air chambers may be into one of the centercompartments 8, the inner end of the casing 9 communicating with atransversely extending air manifold pipe l0 which projects through eachof the partitions l to position a portion of the pipe ll in each of theair compartments. as indicated in Figure 3 of the draw- 'I he pipe IIIis closed at each end and the pipe is externally threaded to receivenuts ii positioned at opposite sides of the respective partitions 1 toprovide an air seal around the pipe and to prevent the escape of airfrom one compartment into an adjacent compartment.

A plurality of valve housings I! of tubular construction projectlaterally from the pipe I!) into the respective air compartments 8, theouter end of each housing I! constituting a valve seat engaged by aconical air discharge valve I3, the valve including a stem H slidablymounted in a guide II secured in the housing and against which one endof a coil spring I6 is positioned and with its other end connected tothe valve stem to exert its influence on the valve for closing the same.

The valves ii for the respective air chambers are responsive to airpressure entering the valve casing 8 and pipe In to open the valves toadmit air into the chambers.

A rod l'l extends longitudinally in the pipe Ill substantiallythroughout the length thereof for engagement with the inner ends of eachof the valve stems ii, the rod having one end of a valve stem I.threadedly connected thereto and extending longitudinally in the valvecasing 8.

The valve casing 9 is formed, on its inside, with a valve seat It.against which a conical valve 20 is engaged and to which the valve stemis is secured.

The valve stem i8 is slidably mounted in a guide 2i secured in the valvecasing 9 and against which one end of a coil spring 22 is engaged andwith its other end engaging the valve 20 to yieldably close the latter.

In the operation of the device, the springs it normally close the valvesll for the respective air compartments 8, while the spring 22 normallycloses the valve 20 in the valve casing 9.

Upon attaching a conventional form of air chuck to the outer end of thevalve casing 9,

the valve stem I8 is moved inwardly, which in turn moves the rod llagainst the inner ends of the valve stems It to also open the valve l3and air is admitted into the respective air compartments 8. ,Uponremoving the air chuck from the valve casing 8, the valves areclosed bytheir respective springs. The several air chambers are thussimultaneously and uniformly inflated and should the tire beover-inflated, the valve stem II is moved inwardly by a suitableinstrument,

which thereby opens all of the valves to simultaneously reduce the airpressure in the several chambers.

In the form of the invention illustrated in Figure of the drawing. thevalve casing 23 extends angularly from the transverse pipe 24 toward oneide of the tire to adapt the device for use on dropcenter wheels.

In view of the foregoing description taken in conjunction with theaccompanying drawings, it

is believed that a clear understanding of the construction, operationand advantages of the device will be quite apparent to those skilled inthis art. A more detailed description is accordingly deemed unnecessary.

It is to be understood, however, that even though I have herein shownand described a preferred embodiment of my invention that the same issusceptible to certain changes fully comprehended by the spirit of theinvention as herein described and the scope of the appended claims.

Having thus described the invention, what I claim is:

1. An inner tube for pneumatic tires having a plurality ofcircumferentially extending, spaced apart partitions forming a pluralityof circumferential air chambers in the tube, an air manifold dischargepipe extending transversely'of the,

chambers through said partitions. an air discharge valve in each chamberfor controlling the discharge of air from said pipe. a valve casing forinflating the tube and communicating with the pipe, a valve in thecasing, a rod extending 1on- 4 gitudinally in said pipe in operativeengagement with each or the valves in said chambers, and a valve stem insaid valve casing and connected to said rod and the second named valvefor opening said first-named valves by an opening movement of the secondvalve.

2. An inner tube for pneumatic tires having a plurality ofcircumierentiaily extending, spaced apart partitions forming a pluralityof circumferential air chambers in the tube, an air manifold dischargepipe extending transversely or the chambers through said partitions, avalve housing in each chamber connected to the pipe, a valve in eachhousing and including a valve stem projecting into the pipe, a rodextending longitudinally in the pipe, and a valve casing connected tosaid pipe and having a valve therein for inflating the tube, saidlast-named valve being connected to the rod for moving the rod intoengagement with the stems o! the first valves to open the latter upon anopening movement of the second valve.

NORVAL ROBERT MADDOX.

REFERENCES CITED The following references are file of this patent:

UNITED STATES PATENTS of record in the Legowsky Nov. 26, 1940

